Energy efficiency is increasingly important for gas-powered appliances, such as hot water heaters, space heaters, and furnaces. In many gas-powered appliances, a flame powered combustion controller is used, where energy from a standing pilot flame is used to power the combustion controller. Thus, no external power source may be required. However, many such systems, if the pilot flame is extinguished, power is lost to the combustion controller.
To improve energy efficiency, intermittent pilot systems have been developed. Intermittent pilot systems typically have a spark ignition system that ignites a pilot flame during each call for heat to the gas-powered appliance. Once the pilot flame is ignited, a main valve of the gas-powered appliance may be activated, allowing the pilot flame to ignite a main burner. Once the call for heat is satisfied, the main burner and pilot flame may be extinguished, thereby saving energy and cost.
Intermittent pilot systems often obtain electrical power after a successful ignition sequence from a thermoelectric device (e.g., a thermopile) capable of generating electricity using the flame from the pilot burner, the main burner, or both. In some cases, electrical energy from the thermoelectric device may be stored in an energy storage device (e.g., a capacitor), which can be used to ignite the pilot flame in response to a subsequent call for heat.
Upon initial installation, or after an extended period of non-use, the energy storage device (e.g., a capacitor) may not store sufficient charge to ignite the pilot flame and/or power the combustion controller. Because of this, many intermittent pilot systems include a piezo igniter. In many such systems, a user is required to manually depress a button to activate the piezo igniter, while at the same time hold down a gas button to open the pilot valve. Once the pilot flame is ignited, the user must continue to hold down the gas button until the pilot flame can heat a thermoelectric device (e.g., a thermopile) or activate a photoelectric device sufficiently to generate enough power to hold the pilot valve open, which in some cases, can take an extended period of time. This procedure can be inconvenient, tedious and error prone for a user.